Work support for blind stitch sewing machines



Jan. 23, 19:10. L R 2,188,229

WORK SUPPORT FOR BLIND STITCH SEWING MACHINES Original Filed June 19, 1937 5 Sheets-Sheet 1 Char/es W Moe/k7 Jan. 23, 1940. c. w. MUELLER 2,188,229

I WORK SUPPORT FOR BLIND STITCH SEWING MACHINES Original Filed June 19, 1937 5 Sheets-Sheet 2 Char/6.9 W/WueV/er Jan. 23, 1940. c. w. MUELLER 2,183,229

WORK SUPPORT FOR BLIND STITCH SEWING MACHINES Original Filed June 19, '19s? 5 Sheets-Sheet s Fig. 5.

Char/es W Mae/Aer Jan. 23, 1940. c. w. MUELLER WORK SUPPORT FOR BLIND STITCH SEWING MACHINES Original Filed June 19, 1937 V 5 Sheets-Sheet 4 Char/es W Mueller Fig. 6.-

Jan. 23, 1940. C MUELLER 2,188,229

WORK SUPPORT FQR BLIND STITCH SEWING MACHINES Original Filed June 19, 1957 5 Sheets-Sheet 5 Ch r/ 4M116 //er Patented Jan. 23, 1940 PATENT OFFICE worm SUPPORT FOR BLIND STITCH SEWING MACHINES Charles W. Mueller, St. Louis, Mo., assignor to Lewis Invisible Stitch Machine Company, St. Louis, Mo., a corporation of Maine Original application June 19, 1937, Serial No.

149,258. Divided and this application November 20, 1937, Serial No. 175,709

12 Claims.

This invention relates to new and useful improvements in sewing machines generally, although more particularly to a work support for blind stitch sewing machines.

This application constitutes a division of my copending application Serial No. 149,258, filed June 19, 1937, for improvements in Sewing machines.

The principal object of this invention is to 2 provide manually releasable means for normally locking the work support against abnormal depression to thereby insure proper feed action of the fabrics, yet permitting a slight depression of the work support to permit not only a variation in the thicknesses of the fabrics being stitched,

but also to permit seams being fed over the ridge forming element.

A further object of the invention is to provide manually operable means for varying the initial position of the work support and the ridge forming element which is mounted thereon, relative to the needle in order to set the machine for a predetermined depth of needle penetration in the fabric or fabrics.

With these and other objects in view which will more fully appear, the nature of the invention will be more clearly understood by following the description, the appended claims, and the several views illustrated in the accompany- 80 ing drawings:

In the drawings: Figure 1 is a top plan view of a machine constructed in accordance with my invention,

Figure2 is'a right hand elevation thereof, the standard being shown in section,

Figure 3 is a bottom plan view of the machine, Figure 4 is an enlarged vertical section showing the work support in its locked or normal position,

Figure 5 is a similar view but showing the work support in its unlocked or fully depressed position,

- Figure 6 is an enlarged vertical section taken on the line 6-6 of Figure 1, the stitching mechanism being omitted; and

Figure 7 is a perspective view of a portion of the main frame showing the post which supports the work support.

Like reference numerals designate corresponding parts throughout the several figures of the drawings.

The sewing machine includes a main frame A which comprises a base 5, a standard 6, an arm I which extends laterally from the upper end of u" the standard and terminates in. a forwardly extending arm 8 which is inclined downwardly and forwardly relative to the base, and a post 9 which is integral with the base and is located at the front thereof and at the right of the arm 8, the post being inclined forwardly and terminata ing at a point in front of and in a horizontal plane below that occupied by the front end of the arm 8.

Rigidly fixed to the forward or free end of the arm 8, is a horizontal presser foot B having 19 the usual centrally located longitudinal opening or slot formed therein, the foot being forwardly and downwardly inclined in a plane disposed in parallelism to the major axis of said arm 8.

Journaled in the upper end of the standard 6 15 and in the arm I is a main shaft 1 l, and journaled in the arm 8 and extending longitudinally thereof is an oscillatory needle shaft [2 having a needle arm l3 fixed to its front, end. The needle shaft 12 has its longitudinafaxis in a 20 downwardly and forwardly inclined plane disposed in parallelism with the presser foot. Attached to the needle arm I3 is a curved needle M.

A work support C is clamped by screws i9 to a 25 horizontal pivot shaft 20' Journaled in spaced bearings 2-1, 2! formed in the post 9 of the main frame. It will be noted that the pivot shaft 20 is disposed in a plane parallel to the main shaft I I and that said pivot shaft is located considerably in front of the needle 14 as well as in front'of the presser foot B. This work support C has its left end reduced to form a horn 22 and projecting laterally from the outer end of the horn is a rectangular frame .23 having an open top and bottom.- This frame 23 is located directly under the presser foot B and includes front and rear walls 24, 25 and an end wall 26.

Operating in the presser foot opening for intermittently projecting anode of fabric upwardly into needle penetrating position, is a ridge forming element D which in this instance consists of a disc fixed to an operating shaft 21 which is journaled at the ends in screwbearings 28, 29, the screw bearing 28 being mounted in a suitable 5 opening formed in the end wall 26 of the frame 23 and the screw bearing 29 being mounted in an opening 3| formed in a lug 32 which depends from the under sideof the work support C. The oscillatory operating shaft 21 is disposed in a horizontal plane in parallelism not only with the main shaft II but also with the pivot shaft 20 of the work support. It will, therefore, be seen that the work support. C extends rear- Wardly from the pivot shaft 20 to a point under the presser foot B and that this work support is capable of swinging downwardly away from the presser foot or upwardly toward the same. It will also be observed that the shaft 21 which operates the ridge forming element D is disposed in rear of the pivot shaft 28 and is movable upwardly and downwardly with the work support and consequently when the work support is lowered the ridge forming element D will be correspondingly lowered with respect to the path of the needle.

The work support C is capable normally of a small free vertical movement about its pivot 20 to permit not only a variation inthe thicknesses of materials being stitched but also to permit seams being fed over the ridge forming disc D. To this end, the work Support C is provided with depending integral front and rear walls 49, 56 respectively arranged on opposite sides of the disc operating shaft 21. A head 5| "includes a horizontal attaching plate 52 and a depending tubular neck 53 having an open lower end. The head 5| is rigidly attached to the lower edges of the depending walls 49, 58 by screws 54, 54. Mounted in said neck for vertical movements relative thereto is a core or support 55. A limiting screw 56 passes downwardly through a non-threaded opening 5'! formed in the plate 52, the lower end of the screw being threaded into the core and thehead 58 of said screw cooperating with the plate 52 to limit the upward movement of the Work support C relative to the core 55. The upper surface of the core is normally spaced below the plate 52 and the upper portion of the core is reduced to form a resultant peripheral recess for receiving a coil spring 59 which engages the bottom wall of the recess and the plate 52 andfunctions to yieldably retain the work support C against downward movement relative to said core.

The core 55 is normally locked against vertical movements, but when the core is moved vertically the work support C, the disc D, and the work clamp supported upon the work support are moved with it as will be evident by reference to Figures 4 and 5 of the drawings. The lower end of the core 55 is provided with a depending lug 68. A toggle is'connected to the lug 68 and to the base 5 of the main frame. The toggle includes a bell crank lever 6| which includes an upright arm 62 and a forwardly extending horizontal arm 63. The lower end of the arm 62 is fulcrumed on an eccentric 64 which is fixed to a horizontal shaft 65, the latter being disposed below the disc operating shaft 21 and in'generally vertical alinement withsaid shaft 21 and with the needle. The ends of the shaft 65 are journaled in the base 5 below the upper surface thereof. ,A normally uprightly disposed link 66 is pivotally connected at its upperend by a pin 61 to the lug and at its lower end by a pin 68 to the upper end of the toggle arm 62, the pin 68 being rigidly secured to the link 66 by a set screw 69. A coil spring 10 is disposed around the projecting end of the pin 68, one end of the spring being anchored in a transverse slot ll formed in the outer end of the pin and the other end of the spring engaging under a stop pin 12 fixed to the link 66.

with the stop shoulder 74 on the bottom of the link .66 in the manner illustrated in Figure to" The spring. 10 functions to yieldably retain the toggle eleprevent the toggle elements passing beyond their locked positions. It will be noted that the arm 62 and the link 66, when in their normal or locked positions, are in generally vertical or upright alinement, i. e., the pivots 6'1, H and are in alinement in a plane which is slightly inclined to the vertical, or in other words, in a plane at right angles to the plane of the foot B. A chain I5 which is adapted to be connected to a treadle or knee-press, has its upper end connected to the forward end of the horizontal arm 63 of said bell crank lever. Thus upon operation of the knee-press or treadle the toggle will be broken and the support or core 55 together with the work support C and parts mounted thereon, will be depressed to permit the ready insertion or withdrawal of the material, and upon release of said knee-press or treadle, the parts will be returned to their normal position by the spring 10. It will, therefore, be seen that when the toggle is in its locked or normal position, the work support C is capable of having a slight vertical movement against the tension of the spring 59 so as to permit various thicknesses of fabrics and seams being fed through the machine.

In order to positively adjust the normal vertical position of the work support C together with the disc D, and thereby set the machine for materials of different thicknesses, I have provided a hand adjusting shaft 76 which is journaled in a bushing 11 mounted in a tubular bearing bracket 18 secured in an opening formed in the front wall of the standard 6. A finger knob 19 is rigidly attached to the front end of the shaft 16 and a spring pressed pin 80 cooperates with the knob to retain the shaft in any position of adjustment. Journaled on the bracket 18 is a worm wheel 8| which is in contant mesh with a Worm 82 formed on the inner end of the shaft 16. Journaled in the base 5 is a horizontal rock shaft 83 having a rock arm 84 fixed to its right hand end, said arm being pivotally connected by a link 85 to the worm gear 8|. The other end of the rock shaft 83 is provided with a rock arm 86 which is pivotally connected to the rear end of a rack bar 81 which extends forwardly along the base to a point below and in front of the eccentric carrying shaft 65. The rack bar 8! is provided along its upper forward edge with rack teeth 88 which engage the teeth of a pinion 89 fixed on said shaft 65. A disc 98 .is journaled on the. shaft 65 and is provided with a pin 9|. forming a support for the front end of said rack bar. A coil spring 92 is connected at one end to the disc and at its other end to the base 5' and functions to urge the pin 9! upwardly whereby the rack bar will be retained yieldably in engagement with the pinion 89. If desired, a coil spring 93 may be provided and attached to the base 5 and the bar 81 as shown in Figure 3 so as to be effective to constantly urge 'the bar forwardly. It will, therefore, be seen that when' the knob .19 is rotated the rack bar 81 will be moved endwise, the shaft 65 together with the eccentric 64 will be rotated, and the work support will be'raised or lowered, depending on the spirit and scope of my invenbination with a frame including a base and a forwardly extending arm, of a horizontal presser foot rigidly attached to the free end of said arm, a work'support mounted on the base to swing about a horizontal axis located. in front of the foot and having a portion disposed under said foot, a vertically movable support for the work support, yieldable means located between the movable support and the work support for permitting a limited downward movement of the work support relative to the, foot, releasable locking meansbetween the movable support and the base .for normally retaining said movable support against downward movement, and manually operable means connected to said locking means' for raising or lowering said locking means together with said movable support.

2. In a :blind-stitch sewing machine, the combination with a frame including a base and a forwardlyextending arm, of a horizontal presser foot rigidly attached to the free end of said arm, a work support mounted on the base to swing about a horizontal axis located in front of the foot and having a portion disposed under said foot, a vertically movable support for the'work support, yieldable means located between the movable support and the work support for permitting a limited downward movement of the work support relative to the foot, releasable locking means between the movable support and the base for normally retaining said movable support against downward movement, said locking means including an eccentric journaled on the base, and a toggle connection between the movable support and the eccentric, and manually operable means connected to said eccentric for rotating the latter to effect the raising or the lowering of said toggle connection together with said movable support.

3. In a blind stitch sewing machine, the combination with a frame including a base, a standard, and an arm extending forwardly from the upper end of the standard, of a horizontal presser foot rigidly attached to the free end of said arm, a work support mounted on the base to swing about a horizontal axis located in front of the foot and "having a portion disposed under said foot, a vertically movable support for the work support, yieldable means located between the movable support and the work support for permitting a limited downward movement of the work support relative to the foot, releasable locking means between the movable support and the base for normally retaining said movable support against downward movement, and means connected to said locking means and including a manually operable control element mounted on the standard for raising or lowering said locking means together with said movable support.

4. In a blind stitch sewing machine, the combination with a frame including a base, a standard, and an arm extending forwardly from the upper end of the standard, of a horizontal presser foot rigidly attached to the free end of said arm, a work support mounted on the base to swing about a horizontal axis located in front of the foot and having a portion disposed under said foot, a vertically movable support for the work support, yieldable means located between the movable support and the work support for permitting a limited downward movement of the support relative to the foot, releasable locking means between the movable support and the base for normally retaining said movable support against downward movement, said locking ,means including an eccentric. journaled on the base, and avtoggle connection between the movoperable means connected to said. eccentric for rotating the latterto effect the raising or lowering of said toggle connection together with said movable support, said manually operable means including a pinion fixed to the eccentric to rotate therewith, a rack bar slidably mounted on the base and engageable with the pinion, a manually operable element mounted on the main frame, and connections between said element and said rack bar for operating the latter.

5. In a sewing machine, the combination of a main frame including a base, a standard, and an arm extending forwardly and downwardly relative to the base from the upper end of the standard; and a work support mounted on the base and having a portion disposed in a horizontal plane below the free end of said frame arm, .said work support being fulcrumed on a horizontal axis to swing upwardly and downwardly relative to said arm, said axis being disposed in a plane at right angles to the longitudinal am'sof said arm.

6. In a sewing machine, the combination of a main frame including a base, a standard, and an arm extending forwardly and downwardly relative to the base from the upper end of the standard; and a work support mounted on the base and having a portion disposed in a horizontal plane below the free end of said frame arm, said work support being fulcrumed on a horizontal axis to swing upwardly and downwardly relative to said arm, said axis being disposed in a plane at right angles to the longitudinal axis of said arm and in front of the free end of said arm.

'7. In a sewing machine, the combination of a main frame including a base, a standard, and an arm extending laterally from the upper end of the standard and terminating in an arm extending forwardly and downwardly relative to the base; and a work support mounted on the base in-front of the laterally extending arm and having a portion disposed in a horizontal plane below the free end of said forwardly extending arm, said work support being fulcrumed on a horizontal axis to swing upwardly and downwardly relative to said free end, said axis being disposed in a plane at right angles to the longitudinal axis of said forwardly extending arm.

8. In a sewing machine, the combination of a main frame including a base, a standard, and an arm extending laterally from the upper end of the standard and terminating in an arm extending forwardly and downwardly relative to the base; and a work support mounted on the base in front of the laterally extending arm and having a portion disposed in a horizontal plane below the free end of said forwardly extending arm, said work support being furcrumed on a horizontal axis to swing upwardly and downwardly relative to said free end, said axis being disposed on a plane at right angles to the longitudinal axis of said forwardly extending arm and in front of the free end of said arm.

9. In a sewing machine, the combination of a main frame including a base, a standard, and an arm extending forwardly relative to the base from the upper end of the standard; a work support mounted on the base and having a portion disposed in a horizontal plane below the free end of said frame arm, said work support being fulcrumed on a horizontal axis to swing upwardly and downwardly relative to said arm, said axis being disposed in a plane at right angles to the longitudinal axis of said arm, a vertically movable support for the work support, yieldable means located between the movable support and the work support for permitting a limited downward movement of the support relative to the arm, releasable locking means between the movable support and the base for normally retaining said movable support against downward movement, and manually operable means connected to said locking means for raising or lowering said locking means together with said movable support.

10. In a sewing machine, the combination of a main frame including a base, a standard, and an arm extending forwardly relative to the base from the upper end of the standard; a work support mounted on the base and having a portion disposed in a horizontal plane below the free end of said frame arm, said work support being fulcrumed on a horizontal axis to swing upwardly and downwardly relative to said arm, said axis being disposed in a plane at right angles to the longitudinal axis of said arm, a vertically movable support for the work support, yieldable means located between the movable support and the work support for permitting a limited downward movement of the support relative to the arm, releasable locking means between the movable support and the base for normally retaining said movable support against downward movement, and manually operable means connected to said locking means for raising or lowering said locking means together with said movable support, the major axis of the forwardly extending arm and the major axis of said locking means being disposed in planes said. axis being disposed in a .plane at right angles to the longitudinal axis of said arm, a vertically movable support'for the work support, yieldable means located between the movable support and the work support for permitting a limited downward movement of the support relative to the arm, releasable locking means between the movable support and the base for normally retaining said movable support against downward movement, and manually operable means connected to said locking means for raising or lowering said locking means together with said. movable support, said locking means including an eccentric journaledon the base, and a toggle connection between the movable support and the eccentric,'and manuallyoperable means connected to said eccentric for rotating the latter to effect the raising or the lowering of said toggle connection together with said movable support, the major axis of the forwardly extending arm and the major axis of said locking means being disposed in planes at right angles to each other.

12. In a sewing machine, the combination of a main frame including a base, a standard, and an arm extending laterally from the upper end of the standard and terminating in an armexe tending forwardly relative to the base; a work support mounted on the base in front of the laterally extending arm and having a portion disposed in a horizontal plane below the free end of said forwardly extending arm, said work support being fulcrumed on a horizontal axis to swing upwardly and downwardly relative to said free end, said axis being disposed in a plane at right angles to the longitudinal axis of said forwardly extending arm, a vertically movable support for the work support, yieldable means located between the movable support and the work support for permitting a limited downward movement of the support relative to the arm, releas' able locking means between the movable support and the base for normally retaining said movable support against downward movement, and manually operable means connected to said looking means for raising or lowering said locking means together with said movable support.

I CHARLES W. MUELLER. 

